Is an exceedance always a non-compliance?

Consider a typical scenario taking place across NSW every day: construction on a major infrastructure project. The contractor has previously assessed the noise impact in a report as required by Regulators. But theactual noise levels exceed the levels in their report. Are they “non-compliant”?Yes, for respite nights when construction noise must not exceed Noise Management Levels (NMLs). By contrast, NMLs can be exceeded on “noisy” nights, but all feasible and reasonable noise mitigation measures must be applied. What is reasonable is related to the predicted level of construction noise—there is an expectation in the community and by regulators that the higher the predicted noise level, the more reasonable it is to implement additional feasible noise mitigation measures. Performance is usually evaluated by monitoring. Monitored noise levels that exceed NMLs, or predicted levels, usually called “exceedances,” can be considered to be non-compliances on “noisy” nights. This approach has some undesirable outcomes, such as encouraging overprediction. A better approach might be to require an evaluation into the reasons why a monitored level is greater than a predicted level, followed by the application of appropriate corrective action. A non-compliance would then only occur if this does not take place.